Wireless communications systems are known that enable wireless data transfer between one or more user equipment (UE) and one or more Base Stations (BS) arranged to provide nodes of a cellular RAN. An increase in the prevalence of UEs operating on wireless cellular communications systems requires that such networks carry and support a wide variety of data traffic types and services. UEs can be viewed as generic computing platforms with wireless connectivity, capable of running a wide-ranging variety of applications and services that are either pre-installed by the device manufacturer or are installed/downloaded by the user according to the user's specific usage requirements. The applications themselves may originate from a correspondingly wide-ranging group of software houses, manufacturers and 3rd party developers. Such UE platforms may include mobile devices such as mobile telephones, ‘smartphones’, personal digital assistants, handheld or laptop computers, tablet computers and similar mobile devices having wireless communications connectivity, or similarly the UE referred to herein could include fixed devices that are relatively immovable in normal use, such fixed devices having wireless connectivity to enable them to communicate using the wireless communications system. The UE platforms may also include other device types comprising embedded communications connectivity, such as household appliances, utility meters and security and surveillance equipment, or consumer electronics devices such as still or video cameras, audio/visual entertainment equipment and gaming platforms.
Wireless communication networks often distinguish between user-plane traffic (which may be considered as carrying application-level user data) and control-plane traffic (which may be considered as signalling used to enable or support transfer of the user plane data via the wireless communication network, including for example mobility control and Radio Resource Control (RRC) functionality). Examples of user plane traffic and services carried by wireless communication networks include voice, video, internet/web browsing sessions, upload/download file transfer, instant messaging, e-mail, navigation services, RSS feeds and streaming media. Examples of control plane traffic include core-network mobility and attachment control (so-called Non-Access Stratum (NAS) signalling), radio access network control (such as Radio Resource Control (RRC)), and session control signalling.
Outside of (or “above”) the radio and core network communication layers, applications may utilise or combine a multitude of internet-based (or other proprietary) protocols to achieve a desired result when provisioning for a specific service. For example, a navigation application may utilise TCP for file transfer of mapping data from a server to a device but may also employ protocols to support periodic or aperiodic keep-alive signalling towards the navigation server to maintain the application-level connection in the presence of intermediary network nodes such as stateful firewalls. Similarly, an e-mail application may employ particular synchronisation protocols to align the mailbox contents on the UE with those in an e-mail server, but may also employ periodic or aperiodic server polling mechanisms to check for new e-mail. The present disclosure concerns operating wireless communication systems to provide UEs with connectivity to support such applications.
For a more complete understanding of this disclosure, reference is now made to the following detailed description that sets out certain embodiments, taken in connection with the drawings, which can be briefly described as follows.